The present invention relates generally to warehouse systems and more particularly to a warehouse system employing a cab-stacker device capable of handling unit loads of elongated and sheet materials and acting as a mobile work-station. In its capacity as a mobile work-station the stacker is capable of stock-picking individual pieces of elongated material from pigeon-hole or cantilever storage racks and subsequently processing such material on the mobile work-station through a light-duty, cut-off operation when required and other operations such as tagging, identifying, bundling and issuing material to interfacing work stations or conveyances.
Various types of devices are in wide use today that are associated with the attainment of the functions described above. One such device employs a stacker crane with a single cab for a one-man operation. The stacker crane can use different lengths of forks or sliding forks handling unit loads, sheet materials and elongated materials. This approach requires the use of pans to hold elongated materials which are stored in cantilever racks. Warehouse methods employed in the past have not used this type of stacker with relatively cheap pigeon-hole racks, which are desirable for storage of slow-moving, light-weight elongated materials.
Sideloader fork-trucks have also been employed in the past. The trucks are guided through narrow aisles by employing guide rails. As in the case of the single-cab, stacker crane, the standard sideloader fork-truck requires pans for handling and storage of certain elongated materials. Furthermore, sideloaders cannot accommodate the use of pigeon-hole racks. Additionally, since the operator of the sideloader usually remains at floor level as the forks are raised and lowered on the hoist column, the operator's visibility has limitations, since unlike the stacker-crane operator his lift forks do not remain at or near operator eye level. This fact creates difficulty in aligning the forks on the vehicle with the arms on the cantilever racks, a problem which becomes more acute as lift heights increase and limits the height to which sideloader fork-trucks can effectively operate. Sideloaders employed in the past are not capable of using pigeon-hole racks, since their forks are aligned with the central axis of the pigeon-hole racks rather than being perpendicular thereto. In addition, both of the above systems are employed simply to move the material from the racks to separate work areas in the warehouse where cutting, identifying, bundling and issuing material to interfacing work stations or conveyances take place.